These diagnostics occurred, but weren't treated as errors:
```
[WARN] Missing return type: alphablend on line 38
[WARN] Missing argument type: dest_bitmap on line 38
[WARN] Missing argument type: source_bitmap_1 on line 38
[WARN] Missing argument type: source_bitmap_2 on line 38
```
mp_obj_float_get gets the value of an object, which must be
exactly a float. mp_obj_get_float gets the float value of
an object of various types, including floats & ints.
This blends two "565"-format bitmaps, including byteswapped ones. All
the bitmaps have to have the same memory format.
The routine takes about 63ms on a Kaluga when operating on 320x240 bitmaps.
Of course, displaying the bitmap also takes time.
There's untested code for the L8 (8-bit greyscale) case. This can be
enabled once gifio is merged.
Convert bitbangio, bitmaptools, _bleio, board, busio, countio, digitalio, framebufferio, frequencyio, gamepadshift, getpass, keypad, math, microcontroller, and msgpack modules to use MP_REGISTER_MODULE.
Related to #5183.
It is required to call .dirty() with appropriate arguments after modifications through the buffer protocol, or the display might not be updated correctly.
When reading uncompressed bitmap data directly, readinto can work
much more quickly than a Python-coded loop.
On a Raspberry Pi Pico, I benchmarked a modified version of
adafruit_bitmap_font's pcf reader which uses readinto instead of
the existing code. My test font was a 72-point file created from Arial.
This decreased the time to load all the ASCII glyphs from 4.9 seconds to
just 0.44 seconds.
While this attempts to support many pixel configurations (1/2/4/8/16/24/32
bpp; swapped words and pixels) only the single combination used by
PCF fonts was tested.
